For singleplayer story:
Emphasis on presentation rather than content since pretty much every story has been told. These games have amazing world building.
• Bastion
• Bioshock 1
• Deponia series
• Deus Ex (1st game and Human Revolution)
• Far Cry 3
• Grim Fandango
• Half Life 2
• Life is Strange
• Okami
• Outer Wilds
• Oxenfree (one of the few indie games with amazing audio design, voice acting, and writing)
• Pokemon Mystery Dungeon (1st two games in the series)*
• Prey (2017)
• Psychonauts 1 & 2
• Pyre
• Star Wars: Knights of the Old Republic
• The Walking Dead: Season 1 (one of the few games that can be alternatively watched instead of played)
• Transistor
• What Remains of Edith Finch

For singleplayer gameplay:
Uniqueness and innovation in their genre are main criteria.
• Animal Crossing series
• Borderlands 2 & 3
• Celeste
• Dark Souls 1 & 3
• Deus Ex (1st game and Human Revolution)
• Enter the Gungeon
• Hades
• Legend of Zelda series (especially Twilight Princess & Skyward Sword)*
• Minecraft
• Okami
• Portal series
• Pokemon mainline series*
• Risk of Rain 1 & 2
• Skyrim
• Super Mario Galaxy*
• The Witness

For co-op (with buddies):
• Borderlands 2
• Heroes of Hammerwatch
• Lego Star Wars: The Complete Saga* (any Lego game honestly)
• Trine series

For the OST:
Ear-gasmic.
• A Short Hike
• Celeste
• Dark Souls 1 & 3
• Gris
• Grim Fandango
• Life is Strange (actually mostly licensed music)
• Okami
• Pyre
• Risk of Rain
• Transistor
• Trine series

For the visuals:
Eye-candy games.
• Astroneer
• Bioshock 1
• Dark Souls 1 & 3
• Gris
• No Man's Sky
• Okami
• Transistor
• Trine series

Favorites:
• Mega Man Star Force*
• Okami
• Pokemon Diamond/Pearl*
• Sleeping Dogs
• The Legend of Zelda: The Phantom Hourglass*
• The Legend of Zelda: Twilight Princess*
• The Witness
*childhood favorites

(last updated 3.28.21)